Firearm safety devices are known and by way of example reference maybe had to U.S. Pat. No. 4,224,753 granted Sep. 30, 1980 to T. F. Bielman. This patent is closely related to the present invention and is the most pertinent reference known to the applicant. The substance of the foregoing patent is incorporated herein by reference thereto.
The Bielman patent teaches a safety device which includes a dummy cartridge that fits into the chamber of the barrel and is connected to a barrel end plug or muzzle cap by a threaded elongate rod. A hand tool is used to un-thread the rod from the dummy cartridge permitting removal of the muzzle cap and rod. Nothing is provided by the patentee that prevents the dummy cartridge from rotating in the chamber when the hand tool is used to un-thread the rod and in some instances this can make the task difficult and perhaps even impossible.
The dummy cartridge of the patented safety device is constructed from an empty shell that has an insert connected to the rear wall of the shell by a shaft anchored in the rear wall. The construction is complicated and therefore relatively expensive to produce as compared to the instant invention. Furthermore no means is provided to protect the gun chamber from the insert and damage thereto that possibly can occur through repeated use of the same.